Glutathione S-transferase pi modulates NF-κB activation and pro-inflammatory responses in lung epithelial cells

Redox Biology

卷:8

Kenneth D. Tew¹  Stevenson Flemer²  James D. Nolin³  Yvonne M.W. Janssen-Heininger³  Xi Qian³  Robert W. Schneider³  Shi Biao Chia³  Vikas Anathy³  Karolyn G. Lahue³  Jos L.J. van der Velden³  David H. McMillan³  Albert van der Vliet³  Jane T. Jones³  Sidra M. Hoffman³  Danyelle M. Townsend⁴ 

[1] Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States;

[2] Department of Chemistry, The University of Vermont, Burlington, VT, United States;

[3] Department of Pathology and Laboratory Medicine, The University of Vermont, Burlington, VT, United States;

[4] Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States;

关键词: NF-κB;    GSTP;    S-glutathionylation;    Asthma;    Inflammation;    Lung;   

DOI  :  10.1016/j.redox.2016.03.005

来源: DOAJ

【 摘 要 】

Nuclear Factor kappa B (NF-κB) is a transcription factor family critical in the activation of pro- inflammatory responses. The NF-κB pathway is regulated by oxidant-induced post-translational modifications. Protein S-glutathionylation, or the conjugation of the antioxidant molecule, glutathione to reactive cysteines inhibits the activity of inhibitory kappa B kinase beta (IKKβ), among other NF-κB proteins. Glutathione S-transferase Pi (GSTP) is an enzyme that has been shown to catalyze protein S-glutathionylation (PSSG) under conditions of oxidative stress. The objective of the present study was to determine whether GSTP regulates NF-κB signaling, S-glutathionylation of IKK, and subsequent pro-inflammatory signaling. We demonstrated that, in unstimulated cells, GSTP associated with the inhibitor of NF-κB, IκBα. However, exposure to LPS resulted in a rapid loss of association between IκBα and GSTP, and instead led to a protracted association between IKKβ and GSTP. LPS exposure also led to increases in the S-glutathionylation of IKKβ. SiRNA-mediated knockdown of GSTP decreased IKKβ-SSG, and enhanced NF-κB nuclear translocation, transcriptional activity, and pro-inflammatory cytokine production in response to lipopolysaccharide (LPS). TLK117, an isotype-selective inhibitor of GSTP, also enhanced LPS-induced NF-κB transcriptional activity and pro-inflammatory cytokine production, suggesting that the catalytic activity of GSTP is important in repressing NF-κB activation. Expression of both wild-type and catalytically-inactive Y7F mutant GSTP significantly attenuated LPS- or IKKβ-induced production of GM-CSF. These studies indicate a complex role for GSTP in modulating NF-κB, which may involve S-glutathionylation of IKK proteins, and interaction with NF-κB family members. Our findings suggest that targeting GSTP is a potential avenue for regulating the activity of this prominent pro-inflammatory and immunomodulatory transcription factor.

【 授权许可】

Unknown